Various manufacturers have offered electronic assemblies including multiple substrates, at least one of which has been a low-temperature co-fired ceramic (LTCC) substrate. In general, LTCC substrates allow for electronic assemblies that have relatively high-density circuitry. However, in electronic assemblies that have incorporated an LTCC substrate, it is often desirable to configure the assembly to improve the thermal conductivity of the LTCC substrate, as LTCC substrates have a relatively low thermal conductivity of approximately 3 Wm/K. This is particularly desirable when LTCC substrates are utilized in high-power applications. In at least one prior art electronic assembly that utilizes multiple substrates, an LTCC substrate has been wirebonded to another substrate. In this assembly, an adhesive bond has been provided in the primary thermal path between the substrates. An additional substrate, which increases the overall package size, has also been implemented within the assembly to improve the thermal conductivity of the electronic assembly. Unfortunately, the utilization of wirebonds between the substrates increases lead inductance and, as such, results in degraded electrical performance of the electronic assembly. Further, application of the adhesive requires an adhesive dispense operation, which increases the process time and cost of the assembly.
What is needed is a multiple substrate electronic assembly that exhibits improved thermal conductivity at a lower cost for both components and manufacturing.